Drinking More of This Classic Tea Improves Focus, Heart Health, and More, RDNs Say

Of all the tea varieties out there (and there are a lot), black tea is among the most popular. If not enjoyed as-is, this tea is often the base for popular blends like chai, Earl Grey, English breakfast, and more.

“Black tea is a type of tea that originated in China and is made from the Camellia sinensis plant—the same plant from which white, green, and oolong tea are made,” says Jamie Adams, MS, RDN, RPYT, women’s health dietitian and founder of Mamaste Nutrition. What sets black tea apart from these other Camellia varieties is the way it’s made—through a process called oxidation.

“The oxidation process involves exposing the tea leaves to air, allowing enzymes to transform their natural compounds, which deepens its flavor and color,” shares Samina Kalloo, RDN, CDN, registered dietitian, nutrition counselor and founder of Samina Kalloo Nutrition.

But aside from black tea’s flavor and versatility, this popular caffeinated beverage actually boasts quite a few health benefits. Read on to discover six of the most impressive ways black tea boosts overall health.

Supports Immunity

The plant compounds found in black tea exhibit antioxidant properties, which can boost immune health. “Antioxidants work by removing free radicals in the body and combating cell damage, both of which may help reduce inflammation and risk of chronic disease,” says Adams. “These powerful antioxidants are formed during the oxidation process,” adds Kalloo. In fact, a 2025 study found that consuming a greater variety of flavonoid rich foods, including black tea, may reduce all-cause mortality and the risk of cancer and other chronic diseases by anywhere from 6% to 20%.

Improves Mental Focus and Alertness

Black tea is often turned to first thing in the morning for a caffeine boost to start the day. And while many people are aware of black tea’s caffeine content, they may not know that it also contains an amino acid called L-theanine. “Both caffeine and L-theanine may improve alertness and cognitive performance,” explains Adams. Recent research echoes this sentiment, highlighting how this specific nutrient combination aids in mental clarity.

Boosts Heart Health

The polyphenols in black tea are even beneficial for those with heart health concerns—or looking to steer clear of them. “Just two cups a day can provide 400 to 600 milligrams of flavan-3-ols, the recommended daily intake to support heart health,” says Kalloo. These plant compounds support heart health through encouraging both healthy cholesterol levels and blood pressure regulation. “A meta-analysis of randomized controlled trials found that black tea supplementation significantly reduced both systolic and diastolic blood pressure compared to control treatments,” explains Adams.

Regulates Blood Sugar

If blood sugar regulation or type 2 diabetes prevention are a top priority for you, black tea can also play a supporting role. “Some research suggests that black tea may offer several benefits for blood sugar regulation,” offers Adams, including this randomized control trial. “Regular black tea consumption has also been linked to a lower risk for type 2 diabetes,” adds Kalloo.

Supports Gut Health

Drinking black tea may encourage a healthier gut, too! For example, a 2023 study found that black tea consumption is tied to improved gut microbiome flora, supporting digestive health, as well as all the other benefits associated with a thriving microbiome, including immune and brain health.

Contributes to Hydration

Surprisingly, black tea can actually contribute to your daily hydration needs. “Both caffeinated and decaffeinated black tea can absolutely count toward your daily fluid intake. When consumed in moderate amounts, caffeinated beverages like tea are as hydrating as water. The fluid you get from tea typically outweighs any mild diuretic effect from the caffeine,” explains Kalloo.

That said, it’s crucial to not go overboard with black tea in pursuit of hitting your fluid goals. “It’s important to consume it in moderation, as excessive intake of caffeine can lead to side effects such as insomnia or increased heart rate,” says Adams—though these effects only occur with excessive black tea consumption. “Caffeinated tea contains approximately 50 milligrams of caffeine per cup, and evidence shows no effect on hydration with intakes of up to 400 milligrams of caffeine per day or the equivalent of eight cups of tea,” explains Kalloo.